requested_toppings = ['mushrooms','green peppers','extra cheese']

if requested_toppings:
    for requested_topping in requested_toppings:
        if requested_topping == 'green peppers':
            print("Sorry,we are out of green peppers right now.")
        else:
            print("Adding " + requested_topping + ".")

    print("\nFinished making your pizza!")
else:
    print("Are you sure you want a plain pizza?")